Radioactive protective apparatus, such as lightning arresters and hail protectors



Aug. 30, 1938. P. GRENIER RADIOACTIVE'PROTECTIVE APPARATUS, SUCH ASLIGHTNING ARRESTERS AND HAIL PROTECTORS Filed Aug. 1o, 195e PO IECEL 71NPatented Aug. 30, 1938 UNITED 4STATES RADIOACTIVE PROTECTIVE APPARATUS,SUCH AS LIGHTNING ARRESTERS AND HAIL PROTECTORS Application August 10,1936, Serial No. 95,154

In Luxemburg 7 Claims.

The eiliciency of apparatus for protection against lightning,thunderbolts, and the like can be much increased by arranging in theneighborhood of the points of such apparatus radioactive bodies, and byapplying to the ions furnished by these bodies an increasing potential.

The methodical observations made in the past few years about thelocalization of falls of hail show that such falls are particularlyfrequent in regions where the ground emits a notable quantity ofnegative ions.

It is thus possible to suppress the falls of hail or to reduce theirquantity by placing on the spots to be protected, devices capable ofemitting positive ions which` will neutralize the negative ions emittedby the ground.

The sign of the ionization is of considerable importance and recentstudies have shown that lightning strikes more frequently in placeswhere negative ionization prevails.

With these considerations in View, the present invention relates tomeansvfor acting not only upon the total ionization of the apparatus inquestion, but also upon the relation between the negative ionization andthe positive ionization with correlative modification and dosedistribution of the proportions of negative and positive ions emitted bythe apparatus.

For this purpose a mixture of radioactive bodies in selected proportionsis used. FSome of these bodies emit only negative ions, and others emitonly positive ions in Well defined proportions.

It is thus possible by a suitable dose distribution of the radioactivebodies, to obtain an emission consisting of negative ions and positiveions in the desired proportion.

If it is intended to strengthen the emissions of a lightning conductorin negative ions it is desirable to form the radioactive element in itsmajor part through bodies having beta rays, such as radium D, actiniumor mesethorium.

If on the contrary it is intended to improve the operation of a hailprotector, it is the emission of positive ions which must bestrengthened, and the radioactive part can be formed mainly of salts ofuranium, or ionium, of polonium, of protoactinium, or of thorium, bodieswhich have an alpha ray.

There can also, in both cases, be made use of, radioactive bodiespossessing both rays and reduce one of them, for instance, the alpharays by means of suitable screens, in such manner as to obtain thedesired ratio between the negative ions and the positive ions.

August 12, 1935 When use is made of a radium salt, it is preferablyselected insoluble, as for example as radium sulphate, which can beobtained through precipitation of a double solution of two solublesalts, for example, radium bromide and barium bromide. The mixture thusprepared is preferably passed through a sieve, in order to obtain grainshaving about the same size.

In the accompanying drawing, which shows by way of example practicalembodiments of devices according to the present invention, Figure 1 is adiagrammatic view of the end of a lightning conductor, with a screen forfiltering the ions.

Fig. 2 is a diagrammatic view relative to the case where the screen isformed on the surface itself of the body of porcelain, and

Fig. 3 is a similar view to part of Fig. 2 drawn to an enlarged scale,illustrating a modification.

In Figure 1, showing the end of a radioactive lightning conductor, l isthe metal stern thereof, 2 is the porcelain carrying radioactive bodies,3 is the thin screen of frusto-conical form, which stops a high ratio ofalpha rays with the positive charge they bear.

In the modification of Fig. 2, the screen is formed by the enamel itselfof the porcelain carrying the radioactive bodies 3. In order to protect,against mechanical and thermal reactions, the radioactive salts, theyare applied in the form of a layer 4 which is embedded in the enamel.The enamel itself forms an outer layer numbered 5 which acts as a screenfor the alpha rays. In order to modify and to adjust the iniiuence ofthe screen, the size of the grains of the radioactive salts aremodified, the density of the enamel and its thickness so as to obtain amore or less marked filtration of the rays.

Referring now to the modification of Fig. 3, 6 is a solid support uponwhich I rst apply an adhesive layer 'l'. Upon this layer are evenlyspread'or diffused the grains 8 of the radium salt or radiferous mixtureprepared as has been hereinbefore described. The surface thus powderedor sprinkled, is then covered or laid over with one or more layers ofthe substance which is intended to act as a screen; the density of thissubstance and the thickness of the final layer 9 enable the filtrationof the alpha and beta rays to be adjusted to the desired value.

The whole is then consolidated by a suitable process such as baking,vitrification, polymerization and the like.

As a more particular example there is hereafter described the adaptationof the previous means, to porcelain having a radioactive layer.

'Ihe member of crude porcelain or steatite is dipped in a bath ofenamel, e. g. o! so called great-fire enamel. 'I'he surface of themember is thus laid over with a somewhat thin layer of enamel whichkeeps soi't and wet for some time. A quantity of a mixture of bariumsulphate and radium sulphate, radiferous salt, which has been carefullysifted, is then taken and put in a state of .suspension in a smallquantity of water. By means of a compressed air pistol this suspensionis atomized upon a wet layer of 'enamel while the member is made to turnregularly or evenly about its axis in such manner as to effect a gooddistribution of the radiferous salt. The member is then left to dry.

If it is desired to obtain the maximum alpha and beta rays the member isallowed to bake for a suitable period. In this case the enamel vitrinesat a temperature which is selected lower than the melting points of themixture of barium sulphate and radium sulphate and thereby enclosed atits surface the grains 8 of this salt. If oppositely it is desired toget a filtration, a further layer 9 of enamel is applied upon themember, preferably with a pistol, the thickness of which layer 9 can beadjusted at will and the whole is then baked. The second layer 9 ofenamel constitutes a thin sheet which covers the grains 8 of theradioactive salt and produces the desired illtration efi'ect.

AAs supplemental advantages inherent to the improved process it is to bementioned that the use of the steatite and of an enamel baked at hightemperature, provides products and articles which are not sensitive totemperature modifications and to solvents of any kind.

In all cases, varnish, paint, or the like, which should be used in asimilar manner, can be substituted for the enamel.

Various other changes might be made without departing from the spiritand scope of the invention as defined by the appended claims.

Having now described my said invention, I declare that what I claim is:

1. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a radioactive substance carried by saidsupport, a screen receiving the radiations emitted by said substance andcontrolling the ratio between the positive ions and the negative ions of-the radiations issuing from said screen.

2. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a plurality of radioactive substancesemitting different radiations and carried by said support, a screenreceiving the radiations emitted by said substances and controlling theratio between the positive ions and the negative ions of the radiationsissuing from said screen:

3. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a plurality of radioactive substancescarried by said support, some of said substances emitting positiveradiations and others emitting negative radiations, a screen receivingthe radiations emitted by said substances and controlling the ratiobetween the positive ions and the negative ions of the radiationsissuing from said screen.

4. In an apparatus for affording protection against lightning andsimilar phenomena; a support, a radioactive substance carried by saidsupport, a screen arranged at a certain distance from said support andreceiving the radiations emitted by said;` substance, said screencontrolling the ratio between the positive ions and the negative ions ofthe radiations issuing from said screen.

5. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a radioactive substance carried by saidsupport, a screen covering the radioactive substance and the support,said screen receiving the radiations emitted by said substance andcontrolling the ratio between the positive ions and the negative ions ofthe radiations issuing from said screen,

6. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a layer of paint covering said support andforming screen, a radioactive substance incorpo rated in said layer ofpaint, said screen receiving the radiations emitted by said substanceand controlling the ratio between the positive ions and the negativeions issuing from said screen.

7. In an apparatus for affording protection against lightning andsimilar phenomena: a support, a layer of adhesive product which, bybaking, has been made insensitive to atmospheric agents and tovariations of temperature, said layer covering said support, aradioactive substance dispersed over said layer, a screen applied onsaid layer, said screen receiving the radiations emitted by saidsubstance and controlling the ratio between the positive ions and thenegative ions of the radiations issuing from said screen.

PIERRE GRENIER.

